Radioreceiver control



y 1933- B. WASHINGTON ET AL 1,918,574

RADIORECEIVER CONTROL Original Filed June 13, 1927 Patented July 18, 1933 UNITED sTATEs. OFFICE Bowman wasnnve'ron, onfNEwroRK, AND WILSON unt, JR., or ASTORIA, YoRmAssIoNoR-sro REMOTE/OLE GORPORATIORA CORPORATION on NEW YORK pR ADIoRECE-IVER common 7 Original application filed June '13, 1927, Serial No. 198,470,

' application filed September 17,1937. Serial No. 220,137,

This application is plieationSerial No. 198,470, filed June 13, 1927, and patented October 4, 1932, No. 1,881,391.'

One object of our invention is to provide a simple and easy manner of turning on and off the filaments of a radio receiver from or near the loud speaker no matter where the latter may-be'located, and without causing a drop of filament voltage at the vacuum tubes which would be the case if the filament current was caused to flow through long extension wires ofsmall cross section.

Another object is to be able to control from a point near thel'oud speaker the;vol-' ume of the sound produced without spoiling the quality. p

Another object is to turn on or off a receiver and control the volume of sound from a point remote from the receiver.

It is becoming morejand more usualto use extension cords sometimes of considerable length in which case the listener has-to goto thereceiverto turn off the filaments. A particular instance of this may be given to show its usefulness in the broadcasting of morning exercises. In this case the radio receiver would normally be placed in the living room, while the user might desire to take exercises in his own room or on a porch immediately upon arising. By means of our invention he could before retiring tune to the station which normally transmits the material for the morning exercises and bring the loud speaker to the exercising place. Upon arising at the predetermined hour he would light the filaments ofhis receiver from or at the loud speaker and adjust the volume to his pleasure, thus puttingrthe set into operation, and upon finishing the exercises turn oil the filaments wlthout the necessity of going downstairs or into another room where the receiver is located.

Fig. 1 shows one form of our invention applied to a radio receiver having a so-called .filtered output from which the direct current componentof the plate current has been eliminated. V

Fig. 2 is a diagrammatic representation of another arrangement of cord extension.

a division of our apavailable may be applied to at n w. 1,881,391. Divided and this Fig. 3 is a detail view of. another modifi- A cation. p In the arrangement shown Fig. 1 particularly intended for power amplifier tube output the plate 5 of the last audio frequency 1 tube 6 of, the set is connected in any suitable manner to a terminal7. The filaments 8 are heated by a suitable source such' as A battery '9." The anodecurrent source or B battery 10 and the A battery in this case have a common terminal 11; The direct current fromltheanode battery is fed to the anode hrough the choke coil 12 while the alternatingcurront or speech component passes through condenser 13. Relay coil 14 is interposed between the A battery andthegterminal 15. The armature '16 and contact 17 constitute an automaticswitch arranged to form a part of the filament circuit when the relay coil 14 is energized. Spring 18 tends tor'hold this circuit. open. 1 r

The loud speaker telephone receiver 20 of any suitable type mayhave the usual cord 21 with terminals 22 and 23i0r connection to the control unit 24. The latter-has three'terminals 25, 26 and 27 connected by conductors 28, 29, and 30 to the 15 respectively of the receiver.

A hand-operated switch hasthe stationary contact 31 and the pivoted switch arm 32 for opening and closing the circuit through the conductor 29, filament battery 9, relay coil 14, conductor 30 and pilot light 33. lVhen this switch is closed the relay magnet 14 draws the armature 16 into contact with 17 and closes the filament circuit of the vacuum tubes ofthe set. The pilot light 33 serves as a silent signal that the filament battery is on. The conductors '28, 29 and 30 may be contained in a single cord extension.

In order to control the volume of the loud speaker a potentiometer may be provided with its'resistance 35 connected across the leads 28 and 29 of its slider arm 36 connected to the loud speaker. By moving this arm 36 any desired fraction of the total voltage the loud speaker 20.

By this arrangement the volume of the loud speaker signals may be varied without terminals 7, 11 and together.

- circuit may be efiected by a single instrument.

I-When the switch arm 32 is swung off the contact 31, the relay 14: is deenergized and the spring 18 opens the filament circuit and thus turns ofi the set. It is assumed of course that the receiver will have suitable amplifying" and detecting means and that tuning to the desired frequency will be done in any suitable manner. V

The control unit may be embodied in the base of the loud speaker 'as-shown in Fig. 3 with a knob 38' for operating it in any well known manner.

The relay I l and its switch element may be embodied in the receiveritself or sold as a separate article of manufatcure for connection to any set. The control elements for the filament and for the speaker volume may be embodied in a unit provided with a cord for attachment to the receiver as shown and the usual speaker andcord can be plugged into it or otherwise connected inthe same man nor as into the usual receivers.

Toavoid having two cables-connected to the control unit as shown in Fig. l.we may run the three wires 28, 29' and 30 through the loud speaker casing l0 as shown in- Fig.2.

to the controlunit 41. These three wires with the two usual loud speaker wires21constitute'a single cable for convenience in installation.

Where wehaveused or anode source in the claims, we, of course, intend'toinclude any suitable source of current. i

We claim: 1. Means for controlling a radlo receiver havlng vacuum tubes and a loud speaker,

'said means consisting of a relay having contacts for opening and closlngthe complete cathode heating circuit of said receiver, said relay being adapted for operation from the cathode heating source, a control box having a voltage divider provided w1th a manual control and adapted to control the input to said loud speaker, and a switch in the operating circuit of said relay connected for operation by the manual control of said voltage divider.

of said receiver, means of connection between the switch and the voltage divider whereby said switch may be actuated by the movable element of said voltage divider. and suitable cableconnections between said receiver, said control unit, and said loud speaker.

,3.- In a vacuum tube radio receiver, a loud speaker, a switch connected to the loud speaker, means for automatically opening all filament heating circuits independently of the B battery and independently of the loud speaker circuits when said switch is open, means at the loud speaker for controlling its volume independently of the filament circuit, and connecting leads between the receiver U 1 and the loud speaker with its control means, the terms A battery B battcry fila1nent source. plate source,

at least one of ,said leads being common to the loud speaker control circuit and the fila- 1 

